coldfusion.eventgateway

Class GenericGateway

java.lang.Object

coldfusion.eventgateway.GenericGateway

All Implemented Interfaces:

Gateway

public abstract class GenericGateway
extends java.lang.Object
implements Gateway

An abstract class that implements some of the ColdFusion event gateway protocol. It uses the Template Method pattern to handle the actual start / stop actions on the concrete gateway.

You can derive from this class, and it will take care of the basic mechanics of implementing a gateway. Your class must implement at least the following gateway operations: startGateway(), stopGateway(), and outgoingMessage().

See Also:

Gateway in Livedocs

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String[]	listeners
protected int	status

Fields inherited from interface coldfusion.eventgateway.Gateway

FAILED, RUNNING, STARTING, STOPPED, STOPPING

Constructor Summary

Constructors

Constructor and Description
GenericGateway(java.lang.String gatewayID) Constructor.

Method Summary

Modifier and Type	Method and Description
java.lang.String	getGatewayID() Return the ID that uniquely defines the gateway instance.
protected GatewayServices	getGatewayServices() Provide access to the ColdFusion GatewayServices object.
GatewayHelper	getHelper() Override this function if you want to provide a helper class for your gateway.
protected java.lang.String[]	getListeners() Return the listeners for this gateway.
int	getStatus() Return the status of the gateway.
void	restart() Restart this gateway.
protected boolean	sendMessage(CFEvent msg) Send an event to the ColdFusion event gateway service.
void	setCFCListeners(java.lang.String[] listeners) Set the CFClisteners list.
void	setGatewayID(java.lang.String id) Set the ID that uniquely defines the gateway instance.
void	start() Start the gateway.
protected abstract void	startGateway() Gateway startup method.
void	stop() Stop the gateway.
protected abstract void	stopGateway() Gateway shutdown method.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface coldfusion.eventgateway.Gateway

outgoingMessage

Field Detail

status

protected int status

listeners

protected java.lang.String[] listeners

Constructor Detail

GenericGateway

public GenericGateway(java.lang.String gatewayID)

Constructor.

If your gateway defines its own constructor (to process a configuration file, for example), include a call to this constructor in your gateway constructor:
super(gatewayID).

Parameters:

gatewayID - The gateway ID string, provided by the ColdFusion MX Administrator.

Method Detail

getGatewayID

public java.lang.String getGatewayID()

Return the ID that uniquely defines the gateway instance.

This function does not typically need to be overridden.

Specified by:

getGatewayID in interface Gateway

Returns:

The gateway ID set by setGatewayID()

setGatewayID

public void setGatewayID(java.lang.String id)

Set the ID that uniquely defines the gateway instance.

This function does not typically need to be overridden.

Specified by:

setGatewayID in interface Gateway

Parameters:

id - Gateway ID string

See Also:

Gateway in Livedocs

setCFCListeners

public void setCFCListeners(java.lang.String[] listeners)

Set the CFClisteners list.

This function does not typically need to be overridden.

Specified by:

setCFCListeners in interface Gateway

Parameters:

listeners - A list of file system paths to ColdFusion components that listen for event messages from this gateway.

See Also:

Gateway in Livedocs

getHelper

public GatewayHelper getHelper()

Override this function if you want to provide a helper class for your gateway.

Return a CFC helper class (if any) so that a CFC can invoke gateway-specific utility functions that might be useful to the CFML developer. The helper class must implement the GatewayHelper marker interface.

Called by the CFML function getGatewayHelper(gatewayID).

Specified by:

getHelper in interface Gateway

Returns:

null - No helper is defined by default.

See Also:

Gateway in Livedocs

getStatus

public int getStatus()

Return the status of the gateway.

This function might need to be overridden if the resource can change status asynchronously from the gateway.

Specified by:

getStatus in interface Gateway

Returns:

one of STARTING, RUNNING, STOPPING, STOPPED, FAILED.

start

public void start()

Start the gateway.

This implementation handles the mantenance of the gateway status only. It calls startGateway which is where you should implement your gateway-specific starting code.

Any exceptions thrown from startGateway() will be logged in the eventgateway.log file.

Specified by:

start in interface Gateway

See Also:

stop, startGateway

stop

public void stop()

Stop the gateway.

This implementation handles the maintenance of the gateway status. It calls stopGateway, which is where you should implement your gateway-specific code.

The method logs any exceptions thrown by stopGateway() in the eventgateway.log file.

Specified by:

stop in interface Gateway

See Also:

start, stopGateway

restart

public void restart()

Restart this gateway.

Implemented as a call to stop() and then start().

You might override this to optimize processing, depending on the service the gateway communicates with.

Specified by:

restart in interface Gateway

See Also:

start, stop, Gateway in Livedocs

startGateway

protected abstract void startGateway()
                              throws java.lang.Exception

Gateway startup method.

You must implement this method with the startup code for your gateway.

Throws:

java.lang.Exception

See Also:

start

stopGateway

protected abstract void stopGateway()
                             throws java.lang.Exception

Gateway shutdown method.

You must implement this method with the shutdown code for your gateway.

Throws:

java.lang.Exception

See Also:

stop

sendMessage

protected boolean sendMessage(CFEvent msg)

Send an event to the ColdFusion event gateway service. This is a utility method for convenience.

Parameters:

msg - The event structure to pass to ColdFusion.

Returns:

true if the event was successfully placed on the queue.

getGatewayServices

protected GatewayServices getGatewayServices()

Provide access to the ColdFusion GatewayServices object.

Returns:

the GatewayServices object.

getListeners

protected java.lang.String[] getListeners()

Return the listeners for this gateway.

Returns:

An array of paths for the gateway's listener CFCs.